Sorry if this has been discussed
I have hard time understand this
Demand: Amount of a physical resource that the object might consume without any existing constraints. An object becomes constrained because of underprovisioning or contention with other consumers of the
resource. A virtual machine might require 10GB of memory but can only get 5GB because the virtual machine must share resources with other virtual machines on the host. When the demand amount is less than the usage amount, the environment might have wasted resources. When the demand amount is greater than the usage amount, the environment might incur latency and exhibit decreased performance.
How could demand amount is less than the usage amount - if resource is not demand how could it be used?
Can anyone shed a light on this?
Thanks